mesopterygium
noun
mesop·te·ryg·i·um
¦me|ˌzäptəˈrijēəm,
¦mē|,
|ˌsä-
: the middle one of the three principal basal cartilages in the pectoral fins of various fishes (as the sharks and rays) compare basipterygium
Word History
Etymology
New Latin, from mes- + Greek pterygion fin, literally, small wing